Ionic conductivity of gamma-Al2O3 and Pb3O4 dopants in 8mol%YSZ as electrolyte in SOFC

Abstract

8mol% YSZ is one of the most common electrolytes for a solid oxide fuel cell (SOFC) due to its high stability at high operating temperatures with good electrical properties. In this work, 8mol%YSZ (8YSZ) were prepared via powder technology and doped with a trivalent dopant of Al+3 and quadrant Pb+4 dopant by a less than l mol% to produce two types of electrolytes: γAl2O3-8YSZ and Pb3O4−8YSZ. The majority of this work is to evaluate the ionic conductivity and study the influence of each dopant Al2O3 and Pb3O4 doped 8YSZ sintered electrolyte via electrochemical Impedance spectroscopy (EIS) at different temperatures from 700°C to 800°C. In addition, the morphology of sintered doped electrolytes was studied with Field Energy Scanning Electron Microscopy (FE-SEM). The chemical characterization analysis with Energy-dispersive X-ray spectroscopy (EDX). The phases of the sintered electrolytes examined with X-ray diffraction (XRD). The resultant ionic conductivity at 800°C for γAl2O3−8YSZ electrolyte was 0.412S.cm and for Pb3O4−8YSZ electrolyte was 0.738S.cm with lower activation energy of 0.575 eV and grain size of 7460nm compared with 0.727 eV for γAl2O3−8YSZ electrolyte and grain size of 8449nm. Accordingly, the Pb3O4−8YSZ is a better candidate to use as an electrolyte at high temperatures.8mol% YSZ is one of the most common electrolytes for a solid oxide fuel cell (SOFC) due to its high stability at high operating temperatures with good electrical properties. In this work, 8mol%YSZ (8YSZ) were prepared via powder technology and doped with a trivalent dopant of Al+3 and quadrant Pb+4 dopant by a less than l mol% to produce two types of electrolytes: γAl2O3-8YSZ and Pb3O4−8YSZ. The majority of this work is to evaluate the ionic conductivity and study the influence of each dopant Al2O3 and Pb3O4 doped 8YSZ sintered electrolyte via electrochemical Impedance spectroscopy (EIS) at different temperatures from 700°C to 800°C. In addition, the morphology of sintered doped electrolytes was studied with Field Energy Scanning Electron Microscopy (FE-SEM). The chemical characterization analysis with Energy-dispersive X-ray spectroscopy (EDX). The phases of the sintered electrolytes examined with X-ray diffraction (XRD). The resultant ionic conductivity at 800°C for γAl2O3−8YSZ electrolyte was 0.412S.cm...